As shown in FIG. 6, a vibration monitoring/analyzing system 1 of a rotating machine conventionally provided has a plurality of vibration sensors 2-1 to n installed on a bearing portion of the rotating machine, transducer circuits 3-1 to n for converting sensor output signals which are vibration information transmitted thereto from the vibration sensors 2-1 to n into analog electric signals proportional to vibration values, a vibration monitor 4 for displaying the analog electric signals transmitted thereto from the transducer circuits 3-1 to n and monitoring abnormal vibrations and giving a warning, an analysis/diagnosis apparatus 5 for analyzing and diagnosing vibrations upon receipt of the analog electric signals transmitted thereto from the vibration monitor 4 and having an A/D conversion circuit, and a personal computer 6 for displaying results of analysis and diagnosis made by the analysis/diagnosis apparatus 5.
The method of wiring apparatuses is as follows: The vibration sensors 2-1 to n are individually connected with the transducer circuits 3-1 to n by using a plurality of analog electric wires AW1. The transducer circuits 3-1 to n are individually connected with the vibration monitor 4 by using a plurality of analog electric wires AW2. The vibration monitor 4 is connected with the analysis/diagnosis apparatus 5 by using a plurality of analog electric wires AW3. The analysis/diagnosis apparatus 5 is connected with the personal computer 6 by using a digital network DN.
When the vibration monitoring/analyzing system 1 analyzes and diagnoses vibrations, the analysis/diagnosis apparatus 5 analyzes and diagnoses the cause of the generation of the vibration by performing transient analysis and FFT analysis of vibration information obtained by the vibration sensors 2-1 to n during one rotation of a rotor of the rotating machine.
However, in the vibration monitoring/analyzing system 1, analog signals are transmitted between the vibration sensors 2-1 and the transducer circuits 3-1 to n, between the transducer circuits 3-1 to n and the vibration monitor 4, and between the vibration monitor 4 and the analysis/diagnosis apparatus 5. Therefore it is necessary to connect them by using the individual analog electric wires AW1, AW2, and AW3. Thus when there are many points at which vibrations are to be measured, it is necessary to use the same number of the electric wires AW1, AW2, and AW3 as that of the points at which vibrations are to be measured. Thus there is an increase in the number of the electric wires and in the amount of the wiring work.
Further owing to the increase in the number of the electric wires, the wiring work is complicated in the field (site) and the maintenance cost increases.
The present invention has been made in view of the above-described problem. Thus it is an object of the present invention to perform an efficient field wiring work for a system for monitoring/analyzing vibrations of a rotating machine.